Objectives The California Regional Primate Research Center (CRPRC) has served for ten years as a centralized Primate Testing Facility (PTF) for the Contraceptive Development Branch (CDB) of the National Institute of Child Health and Human Development (NICHHD). The purpose of this contract is to house and maintain a colony of cynomolgus monkeys (Macaca fascicularis) as well as use them in the conduct of experiments designed to test the safety and efficacy of contraceptive agents prior to being tested in humans. The cynomolgus monkey was chosen for these studies because of its size, lack of seasonality and its similarity to humans in many aspects of reproductive function. All animals are maintained under normal CRPRC guidelines for animal care. At the present time most agents being tested are either synthetic steroids which exhibit either progestational or androgenic effects, or immunocontraceptive vaccines, which could provide safe, effective and convenient birth control for women and men, especially those in developing countries where access to medical care is limited. Results Currently there are two studies being conducted. One of the studies is a fertility trial, in which a group of normal cycling females will be given either a sperm antigen or control treatment regimen, followed by a breeding phase to test contraceptive effectiveness. The other project being conducted is a pharmacokinetic study or oral treatment with levonorgestrel (LNG) in either tablet or capsule form. Future Directions There are plans for more immunocontraceptive studies and kinetic studies in the future. KEY WORDS contraceptives, steroids, immunocontraceptive, levonorgestrel FUNDING NIH Grant HD63247